To disable ccid on scdeamon, the user can run:

    printf 'disable-ccid:0:1\n' | gpgconf --change-options scdaemon > /dev/null

but if ~/.gnupg/scdaemon.conf doesn't exist before this is run, this produces
the warning to stderr:

gpgconf: warning: can not open config file /home/user/.gnupg/scdaemon.conf:

No such file or directory

This warning is not useful or meaningful (there's nothing the user can or should
do about it) and it encourages people to ignore warnings from gpgconf. It
should be suppressed.